Role of dams in mitigating the Impacts of climate change

India has distinct topological and geographical features which results in varying climatic zones ranging from the arid Thar desert in north-western part, Humid areas in south-western region, central and north-eastern parts, Himalayan tundra in the northern regions. Further, there are diverse micro-climatic areas that spread across the vast sub-continent. A dominant and key feature of regional climate is ISM (Indian Summer Monsoons). The ISM also exhibits a rich variety of natural variations on different timescales ranging across sub-seasonal/intra-seasonal, inter-annual, multi-decadal and centennial timescales, which are evident from instrumental records and paleo-climate reconstructions. Results from studies simulating the past climate using paleo-climate proxies indicate that the changes recently observed in global surface temperature are unusual and the natural processes alone cannot explain the rapid rate of warming since the industrial era. The annual mean near-surface air temperature over India has warmed by around 0.7°C during 1901–2018 with the post-1950 trends attributable largely to anthropogenic activities. Atmospheric moisture content over the Indian region has also risen during this period. The mean temperature rise over India by the end of the twenty-first century is projected to be in the range of 2.4–4.4°C across greenhouse gas warming scenarios relative to the average temperature over 1976–2005. With the resultant increase in temperature and atmospheric moisture, climate models project a considerable rise in the mean, extremes and inter-annual variability of monsoon precipitation by the end of the century. With extremes and inter-annual variability of monsoon precipitation, the role of dams becomes extremely important in mitigating the impacts of climate change for water security, dam safety, flood mitigation etc. This requires formulation of new plans and strategies for management and operation of existing as well as future water resources projects. In the present paper scenario of climate change for Indian sub- continent, its impact on water security, hydropower, floods and dam safety has been discussed.